Two-level temperature thermostat



J. M, LARsoN I Two-LEVELTEMPERATURE THERMOSTAT Filed May 25. 1931 3 Sheets-Shea?I 1 l i/zwem.

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l TWO-LEVEL TEMPERATURE THERMOSTAT Filed May 25,;19-s1 V s -sheets-sheet 2 "I l jaa/@771 Fe. 27. 1934. J, M. LARSON TWO-LEVEL TEMPERATURE THERMOSTAT Filed May 25,'- 1931 3 Sheets-Sheet 3 www.

Patented' Feb. 27, 1934 UNITED STATES PATENT OFFICE John M. Larson, Chicago, Ill., assignor to National Regulator Company, Chicago, Ill., a corporation Yof Illinois Application May 25, 1931. Serial No. 539,769

1,9 Claims. (Cl. 236-87) My invention relates to a two-level temperature thermostat construction.

Oneof the objects of my invention is to provide an improved two-level temperature thermostat construction in which the control is ei- A further object is to provide such a construc-` tion which willbe durable and efcient in use.

Further objects will appear from the description and claims.

In the drawings, in which several embodiments oi my invention are shown,

Figure l is an axial section oi a thermostat embodying my invention;

Fig. 2 is a section on the line 2-2 of Fig. l;

Fig. 3 is la section on the line 3 3 of Fig. 2;

Fig. 4 `is a view from the right oi the lower end of Fig. l;

Fig. 5 is a view similar to Fig. 1 but showing the electric control for the temperature level;

. 3G Fig. 6 is a diagrammatic view showing the radiator valve controlled by the thermostat of Fig. 5;

Fig. 7 is a view similar to Fig. 5 but showing the electric control for the radiator valve and electric control for the temperature level; l

, Fig; 8 is adiagrammatic View showing a radiator valve controlled by the thermostat ofAFig. 7; and

Fig. 9 is a detail view showing the radiator valve and electric actuator of Fig. 8

In Figs. 1 to 4 inclusive of the Ydrawings is shown a two-level temperature thermostat construction comprising a heat extensible tube 1, a screw plug 2 closing the end of said tube, a temperature-controlling valve 3 in said tube, carried by said plug and controlled by the expansion and contraction of said tube, transmission from said tube to said valve, spring means 4 in said tube carried by said plug for modifying the action of the valve 3 to change the temperature level,

pneumatic means5 carried by said plug for shifting said spring 4 from nonmodifying to modifying position, an 'adjustable screw 6 carried by said plug for adjustably limiting the movement of the spring 4 under the action of said pneumatic means, manually operable means 7 carried by said plug for rendering said pneumatic means ineffective when desired, a restricted air passage in said plug leading from a source of compressed air to a pneumatic motor 82L for a 60, radiator valve Sb (Fig. 6), vented by said tempeinture-controlling valve 3, and an air passage El in said plug leading to the pneumatic spring shifting means .5.

Betere describing in greater detail certain S5 features oi' the construction, l will briefly outline the operation.

rl'he air passage l@ (Fig. 2) is connected with a suitable source oi compressed air, the passage il is connected with a pressure-closed radiator i@ valve, and the passage Q is connected with a inanually-controllable source of compressed air which can be 'turned on or oi as desired to change the temperature level. Assuming that it is desired to maintain the high level day-time temperature, the valve modifying spring 4. will be in the position shown in Fig.

Assuming that the pressure-closed radiator valve has been open 'for a time and has raised the room temperature up to or slightly above the de- BG sired day-time temperature level, the heat extensible tube l will have expanded allowing the ventcontrolling valve 3 to close the vent port 12 under the action or" the leaf spring fulcrum 13 supporting the valve actuator lever le, the tension S5 of the spring 13 acting to close the valve 3. lThis will'cause pressure to be built up in the pneumatic device which operates the radiator valve and will cause this radiator valve to close; cutting off the heat. This will cause the room temperature to lower, causing the heat extensible tube 1 to contract to move the spring mounted valve-controlling lever 14 to the right to release its pressure on the valve 3, permitting the valve 3 to open the vent port 12 under the action of the spring Iul- 95 crum 15 on which the valve is mounted, the tension in the spring 15 tending to open the valve 3. This will vent the air from the pneumatic power device which controls the radiator valve faster than it can be supplied from the passage 8 100 past the flow-reducing screw 16 which is adjusted to permit just the correct amount of flow for proper operation. The venting of the pneumatic power device which closes the radiator valve permits the radiator valve to open under the action of a suitable spring, thus causing the radiators to heat up again to raise the room temperature. This cycle of operation is repeated to maintain the room temperature substantially at the desired day-time level.

In order to put into effect the desired subnormal or night-time temperature, the operator supplies compressed air through the passage 9 underneath the diaphragm 5 which raises the plunger 17 and rocks the lever laan which the temperature-modifying spring 4 is mounted to bring the upper end of the temperature-modifying leaf spring 4 into engagement with the lower end of the spring-mounted lever 14 which controls the vent-controlling valve 3. The distance to which this rock lever is moved by the action of the lunger is determined by the adjustable screw 6 threaded into the plug :2 and having a reduced extension 19 in viosition to be engaged by the extension 20 of the rock lever on which the spring is mounted. By adjusting this screw 5, the amount of spring pressure which the temperature-modifying spring exerts may be determined to an exact degree.

When this spring 4 is thus moved to temperature-modifying position, it holds 'the spring mounted valve-controlling lever 14 against the vent-controlling valve 3, holding the vent-controlling valve against the vent port'12 until the heat extensible tube 1 contracts to an extent sufficient to overcome the resistance of this temperature-modifying spring 4, which necessitates a ilexing of the leaf spring mounting at the point 21 to an extent sunicient to set up a tension in this lea!` spring which will overcome the resistance of the temperature-modifying spring 4. This means that the heat-extensible tube will have to contract to a greater extent to permit the vent-controlling valve 3 to open when the temperature-modifying spring 4 is in modifying position than is the case when the temperaturecontrolling spring 4 is not in temperature-modifying position. Under these conditions, therefore, the action of the thermostat will include the same cycle of operations as previously outlined in connection with the maintenance of normal day-time temperature but with the exception that the temperature level maintained will be lower because of the greater degree of contraction oi' the tube necessary for the opening of the vent va ve.

The transmission from the tube 1 to the actuator'14 comprises a push rod 22, the lower end of which bears on a block 23 secured tothe spring 13, and forming a lever arm for the valve actuator 14. The upper end of the push rod is engaged by the adjusting screw 24 which determines the normal day-time temperature level.

It is common practice to provide a plurality of these thermostats in the various rooms of a building and have the temperature-modifying springs 4 all controlled collectively by means of branch conduits leading from a central manually-controllable pressure control valve. In such an installation it may befdesirable to maintain a normal day-time temperature in one of theV rooms at a time when the majority of the rooms are to be maintained at the low-level night temperature. For this purpose a manually-operable rock shaft 25 is provided having alaterally-extending arm 26 which can be turned down so as to bear against and force downwardly the button 27 which rests on the pressure-operated diaphragm 5, thus forcing the plunger downwardly and permitting the spring 4 to drop to a positionfin which it does not engage the valvecontrolling lever '14 and permitting the thermostat to operate on the normal temperature basis. lZUhe pressure between the end of the arm 26 and the button 27, (due to the fact that there is cient to hold the arm in its downwardly-extending position against the action of a suitable counterweight or spring tending to raise the arm to horizontal position. As soon, however, as the central control is operated to relieve the pressure underneath the diaphragm 5, the pressure between 'the button 27 and the end of the arm 26 will be relieved, permitting, the arm to be returned to horizontal position under the action of the aforesaid spring o1' counterweight. This return or" the arm to horizontal position will restore the thermostat in question to the central control soy that thereafter it can be controlled with the other thermostats collectively.

It will be noted that the principal working parts of the thermostat are mounted on the plug 2 Vwhich is screwed into the end of the heat-extensible tube 1. rThis makes a self-contained assembly so that the operating parts stay in adjustment and are protected from injury by being housed in the heat-extensible tube.

The provision of the valve-operating lever 14 between the spring 4 and valve 3 enables a bearing pressure to be exerted on the valve which is directly in line with the vent port 12, thus causing the valve to seat evenly under all conditions, regardless of the adjustment which may be made for the temperature-modifying spring 4.

The lever 18 on which the temperature-modifying spring 4 is mounted may be pivoted in a suitable bearing bracket 28 screwed intothe plug 2.. The diaphragm which operates the plunger button may be held in position by meansy of an apertured retaining disc29, the edge of which is forced against the edge of the diaphragm by means of a coil compression spring 30 seated in a pocketin the screw cap 3l.

It will be seen that the device described may be used to maintain selectively two different temperature levels by means of a single vent-controlling valve 3 and a single thermostatic element 1; that the principal moving and workingparts are completely housed and protected against injury; that the adjustments for the two temperature levels may be effected from the outside of the housing, and that the low level temperature adjustment may be made without actually necessitating that the room temperature shall drop tothe minimum temperature which it is desired to maintain.

This adjustment is accomplished as follows: It will be assumed that the normal temperature level is to be 70 degrees and the low or night temperature level, 40 degrees. This means that- -the normal level is 30 degrees above the low temperature level. To secure the desired low level temperature adjustment while the room temperature is still at approximately 70 degrees, the adjusting screw.. 24 for the normal level`-temperature adjustment is turned up adjustment will be made known by the slighty Y noise of the escaping air. The pressure is then released underneath the diaphragm 5, allowing the spring 4 to move to non-modifying position, and the normal temperature adjusting screw 24 is tumedback to the normal setting of '10 degrees. The parts are now in position to maintain normal daytime temperature, when there is no pressureunderneath the diaphragm 5, and to maintain a temperature of degrees below normal (that is a degree temperature), when pressure is supplied underneath the diaphragm' 5 and the spring 4 is moved to temperaturemodifying position.

The construction shown in Figs. 5 and 6 is substantially the same as that shown in Figs. 1 to 4 inclusive, except that here the spring means 4 which control the temperature level are controlled by a solenoid 32 and switch 33 controlling the circuit 33a of the solenoid. The solebutton 27 of Fig. l. When the switch 33 is closed,

the coil 3? of the -solenoid 32 is energized and the plunger 36 rises, making the leaf spring 4 effective to change the temperature level.

The construction of Figs. 7, 8 and 9 is substantially the same as that of Figs. 5 and 6, except 'that here electrical means are provided for operating the radiator valve controlled by a pair of spring contacts 3d in the heat-extensible tube i. These spring contacts 38 are controlled by means or" a lever 39 mounted on a spring iulcrum member 40 which is in turn mounted on the post carried by the plug 2. The position 'of this lever is controlled by the expansion and contraction o the tube l through the action of the push rod 22. When the tube l expands with the heat, it permits the lower end or the spring-mounted lever 39 to move to the left, as seen in Fig. 7, under the tension of the spring fulcrum 4G, closing the circuit between the two springccntacts 3S. This completes the circuit 41e for 'the coil 42 of the solenoid 43 which controls the radiator valve 8b, causing the plunger or core 44 of the solenoid to be moved downwardly to close the radiator valve, thus closing off the heat.

The change of temperature level is eiected just as in the construction of Figs. 5 and 6 by closing theY switch 33 which controls the circuit 33B for the temperature level solenoid 32.

The location of the contacts inside the heat extensible tube 1 has a: special advantage in that the contacts are protected from dust and foreign substances which would interfere with their and contraction of said tube, a `plug fcrthe end of said tube,yielding resistance means for modifying the action of the valve to change the temperature level, and a member movably mounted on said plug, said yielding resistance means being mounted on said movable member and movable therewith into and out of temperature-modifying position.

2. In a temperature control system, a two-level temperature thermostat construction comprising contraction of said tube, a plug for the end of said A tube, yielding resistance means mounted on said .plug for modifying the action of the valve to change the temperature level, and pneumatic means for' controlling the action of said yielding resistance means.

I.3.'In a temperature control system, a two-level temperature thermostat construction comprising a heat-expansible tube, a temperature-controlled 'valve in said tube controlled by the expansion and contraction of said tube, a plug for the end of said tube, yielding resistancemeans mounted on said plug for modifying the action of thevalve to change the temperature level, and pneumatic means mounted on said plug for controlling the action of said yielding resistance means.

4. In a temperature control system, a two-level temperature thermostat construction comprising a heat-expansible tube, a temperature controlled valve in said tube 'controlled by the expansion and contraction of said tube, a plug for the end of said tube, movable yielding resistance means mounted on said plug for modifying the action of the valve to change the temperature level, and pneumatic means for moving said yielding resistance means.

5. ln a temperature control system, a two-level temperature thermostat construction comprising a heat-expansible tube, a temperature-controlled valve L1 said tube controlled by the expansion and contraction of said tube, a plug for the end of said tube, movable yieldingresistance means mounted on said plug for modifying the action of the valve to change the temperature level, and pneumatic means mounted on said plug for Inoving said yielding resistance means.

5. In a temperature control system, a twou level temperature thermostat construction comprising a heat-expansible tube, a screw plug closing the end of said tube, a temperature-controlled valve in said tube, carried by said plug and controlled by the expansion and contraction or' said tube, transmission from said tube to said valve, yielding resista-nce means in said tube carried by said plug for modifying the action of the valve to change the temperature level, pneumatic means carried by said plug for shifting said yielding resistance means from non-modifying to modifying position, adjustable means carried ,by said plug for adjustably limiting the movement or" the yielding resistance means under the action of said pneumatic means, manually operablev means carried by said plug for rendering said pneumatic means ineffective when desired, arestricted air passage in said plug leading from a source of trolled valve in said chamber controlled by the expansion and contraction of said chamber. yielding resistance means for modifying the action of the valve to change the temperature level, pneumatic means for controlling the action of said yielding resistance means; and manually controllable meanslfor selectively counteractlng the effect of the pneumatic means.

, 8. In a temperature control system, a two-level temperature thermostat construction comprising 1 a heat-expansible chamber, a temperature-conlll@ trolled valve in said chamber controlled by the expansion and contraction of said chamber, yielding resistance means for modifying the action of the valve to change the temperature level, pneu-- matic means for controlling the action of said yielding resistance means, manually controllable means for selectively counteracting the effect of the pneumatic means, and means whereby lthe pneumatic means may be controlled for resetting the manual counteracting means.

9. In a temperature control system, a two-level temperature thermostat construction comprisinga heat-expansible chamber, a temperature-controlled valve in said chamber controlled by 'the expansion and contraction of said chamber, yielding resistance means for modifying the action of the valve to `change the temperature level, and electric means for controlling the action of said yielding resistance means.

lo. In a temperature control system, a twolevel temperaturethermostat construction comprising a heat-expansible chamber, a temperature-controlled controlling device in said chamber controlled by the expansion and contraction of said chamber, yielding resistance means for modifying the action of the controlling device to change the temperature level, and electric means for controlling the action of said yielding resistance means.

1l. In a temperature control system, a two-` level temperature thermostat construction comprising a temperature-controlled controlling device, movable yielding resistance means for modifying the action of the controlling device to change the temperature level, and electric actuating means for moving said yielding resistance means.

12. In a` temperature control system, a twolevel temperature thermostat construction comprising a temperature-controlled electrical controlling device, movable yielding resistance means for modifying the action of the controlling device to change the temperature level, and electric actuating means for moving said yielding resistance means.

13. In a temperature control system, a twolevel temperature thermostat construction comprising a heat-expansible tube, a temperaturecontrolled valve in said tube controlled by the expansion and contraction of said tube, a plug for the end of said tube, yielding resistance means mounted on said plug for modifying the action of the valve to change the temperature level, and electric means mounted on said plug for controlling the action of said yielding resistance means.

14. In a temperature control system, a twolevel temperature thermostat construction cornprising a, heat-expansible chamber, circuit controlling means in said chamber controlled by the expansion and contraction of the chamber, remote .control means for modifying the action of said circuit controlling means to change the temperature level, and manually operable means for nullifying the effect of the remote control means.

15. In a temperature control system, a twolevel temperature thermostat construction comprising a heat-expansible chamber,` a temperature-controlled flow controller "in said chamber controlled by the expansion and contraction of said chamber, and means for changing the temperature level control from one definite level to another definite level .comprising a. spring movable to one definitely-located position in which it exerts a definite spring action on said flow controller for causing one definite temperature perature level to be maintained, means for causing said spring to be moved from one deilniteiylocated. position to the other to change the temperature from one definite predetermined level to another definite predetermined level, and transmission between said heat-expansible chamber and said flow controller whereby said chamber may cause force to be exerted on said flow controller, said thermostat construction comprising yielding lost motion means acting between the heat-expansible chamber and spring when the spring is in said rst position and the heat-expansible chamber is causing force to be exerted on said ow controller.

i6. In a temperature control system, a twolevel temperature thermostat construction comprising a heat-expansible chamber, a temperature-controlled fiow controller in said chamber controlled by the expansion and contraction of said chamber, and means for changing the temperature level control from one definite level to another definite level comprising a spring movable to one definitely-located position in which it exerts a definite spring action on said flowcontroller for causing one definite temperature level to be maintained and movable to another definitely-located position in which the spring does not exert the same definite spring action on said flow controller as it did in said first definitely located position for causing the other temperature level to be maintained, means for causing said spring to be moved from one deflnitely-located position to the other to change the temperature from one definite predetermined level to another deiinite predetermined level, said heat-expansible chamber comprising a heat extensible tube and said spring being mounted in said tibe, and transmission between said heat-expansible chamber and said flow controller whereby said chamber may cause force to be exerted on said flow controller, said thermostat construction comprising yielding lost motion means acting between the heat-expansible chamber and spring when the spring is in saidv iirst position and the heat-expansible chamber is causing force to be exerted on said now controller. l

17. In a temperature control system, a twolevel temperature thermostat construction comprising a heat-expansible chamber, a. temperature-controlled flow controller in said chamber controlled by the expansion and contraction of said chamber, and means for changing the temperature level control from one definite level t0 another definite level comprising a. spring movable to one definitely-located position in which it exerts a definite spring action on said flow controller for causing one definite temperature level to be maintained and movable to another definitely-located position in which the spring does not exert the same definite spring action on said flow controller as it did in said first definitely located position for causing the other temperature level to be maintained, means for causing said spring to be moved from one definitely-located position to the other to change the temperature from one definite predetermined level to another definite predetermined level, said. heat-expansible chamber comprising a heat-extensible tube, and a plug closing the endof said tube, the spring being in said tube and mounted on said plug, and transmission between said heat-expansible chamber and said flow controller whereby said chamber may cause force to be exerted on said ilow controller, said thermostat construction comprising yielding lost motion means chamber and spring when the spring is in said first position and the heat-expansible chamber is causing force to Vbe exerted on said flow controller.

18. In a temperature control system, a twolevel temperature thermostat construction comprising a heat-expansible chamber, a temperature-controlled flow controller in said chamber controlled by the expansion and contraction of said chamber, and means for changing the temperature level control from one denite level to another definite level comprising a spring movable to one definitely-located position in which it exerts a denite spring action on said flow controller for causing one definite temperature level to be maintained and movable to another denitely-located position in which the spring does not exert the same denite spring action on said flow controller as it did in said rst denitely located position for causing the other temperav ture level 'to be maintained, means for causing acting between the heat-expansiblel said spring to be moved from one definitelylocated position to the other to change the temperature from one definite predetermined level to another denite predeterminedlevel, and adjustable stop means for selectively changing one of the said denitely limited positions.

19. 1n a temperature control system, a twolevel temperature thermostat construction cornprising a heat-expansible chamber, a temperature-controlled flow controller in said chamber controlled by the expansion and contraction of said chamber, and means for changing the temperature level control from one denite level to another definite level comprising a spring movable to one definitely-located position for causing one denite temperature level to be maintained and movable to another definitely-located position for causing the other temperature level to be maintained, means for causing said spring to be moved from one denitely-located position to the other to change the temperature from one definite predetermined level to another definite predetermined level, and remote control means for shifting said spring from one of said definitelylocated positions to the other definitely-located position.

JOHN M. LARSON.

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